Retrofitting old Injection Press

[Jim Estes]

I bought 3 BOY 15s injection molding presses. I have one running and the other two will need a lot of work to get them running. I am interested in possibly retrofitting them with Allen Bradley PLCs. Does anyone have any information about how to do this? or know of any companies that do this sort of thing? I worked at a company that had several machines that had been retrofitted, but I never knew who had done the work.

Any help you can provide is greatly appreciated.

Thanks,
Jim

[Al_The_Man]

Are you commited to A-B? They are not the cheapest PLC to go with.
Apart from the normal I/O, do you know if there are any special interface features needed?
The way to find out if you live in a large metropolitan area is to contact the Large electrical suppliers in the area, as they are usually reps. for PLC's and work with local PLC integrators.
If you have a contact at the previous company that would let you have a copy of the ladder (if the same machine), it would save a great deal of money.
Al.

[Jim Estes]

No I'm not stuck on AB, I just have seen several of them used on these old presses, so I figure someone is making money doing these retrofits. I checked ebay, and there are a lot of AB PLCs available at low cost. I have a friend who does programming for a large company that uses nothing but Mitsubishi PLCs I might go with that. What seems to be the hardest part about doing this would be keeping the swithes that allow for maunal operation of the machine for setup. Also, these machines need to operate in three different modes, manual, semi-automatic (requiring operator to open and close the door), and automatic. Everything on the machine is either controlled by a switch or a timer.

[Al_The_Man]

Mitsubishi make a nice unit, they come up on Ebay fairly cheap.
The outputs that the Manual buttons control are probably going to be output on the PLC so it is probably going to be better to control all functions on the PLC, Man,semi & Auto.
This way it maximum flexibility, once you have everything into the plc, its just a question of programming, and any changes needed do not need re-wiring, that the beauty and strength of going PLC.
Al.

[Wiseco]

On our own build machine, we use Fanuc PLC to control them but as AI_The_Man said, our older manual setup was to act directly on relays that control everything(valve solenoid starter...). For our new machine, we all passed through the PLC so we can add safety feature in manual process.

I never tryed them yet but Automation direct have some cheap PLC that seems to be popular.

The first thing I would advice you is to find the electrical schema of that machine. If you can have a hand on it, it would save you times. If you cannot have it, take away all wirings and stuff! Most of times it's more quick to rewire everything compare to try to find which wire do what.

If you have money to build something great, I would say go for HMI to control all your machine, like controlling temperature, controling valve solenoid... everything! After that, if you need to know a specific value (times, counts, how many cycle, switch glitching problem...) or add special process feature (safety, close-loop motion...) you will only have to program it. Also, you would have everything you need to setup at one only place, the screen!

[Al_The_Man]

Originally Posted by Wiseco If you have money to build something great, I would say go for HMI to control all your machine, like controlling temperature, controling valve solenoid... everything! After that, if you need to know a specific value (times, counts, how many cycle, switch glitching problem...) or add special process feature (safety, close-loop motion...) you will only have to program it.

For HMI, Maple Sytems offer products that will interface with most PLC's, these are a cheaper way to go than the A-B's, Fanucs's own etc.
Al.

[Wiseco]

Yeah I agreed but Automation direct offer HMI too so... I and I will never use A-B product for the price they want.

[Al_The_Man]

Originally Posted by Wiseco Yeah I agreed but Automation direct offer HMI too so... I and I will never use A-B product for the price they want.

I know what you mean, but when I can by 4 SLC500 self-contained units for $200 on ebay, I have only one thing to say.
Where was EBAY 20 years ago when I could have really used them?
Al.

[Jim Estes]

I looked into the AB Proset 200 package. From what I found it seems to be around $7000 minimum for the package new. that's way too much for these old machines, and I don't really need all the closed loop stuff. These machines aren't going to be used for high presicion stuff, or even high production. I think ebay can do better, if I can just figure out what I need. I really don't need the touch screen and such, but I found a couple on ebay for a few hundred bucks, so why not. I figure it will be easier if I just strip the machine and start from scratch. I have one machien running, so I will keep the guts from the other two for spare parts.
Most of the functions are controlled by position swtiches, actuated by adjustable stops on round bars. Nothing too complicated. There are only three heater bands, and three timers to control the injection, cooling and ejection strokes. One thing that I have no idea about it the hydraulics. I need to find some schematics for it to figure out what is there.

Any more info you guys have is greatly appreciated.

BTW, here is a link to a thread about just this sort of thing.
http://www.plctalk.net/qanda/showthr...ection+molding

Jim

[Al_The_Man]

It would seem from that link that the process is more complicated than I thought, although if you don't have the sophistication on the machine right now, all you would need to do is re-produce what you have.
Obviously schematics are a must.
Al.

[Jim Estes]

Yeah, I want to definitely keep it simple. I don't need all the bells and whistles of the Proset. these little machines just spit out simple parts all day when they are runing. I have been around them for years, just never tried to upgrade one of them.

[Wiseco]

So if you want something simple, you could use a shoe-box PLC (micro PLC) like a DL105 or a versamax micro from Fanuc. It's what we used in our first machine and they work great. Ge Fanuc also have starter kit which include the software, cables and the PLC for about 400$. It could control the motion of the machine but for controlling the barrel temperature, you should go with some Omron Temp. controller like E5CN I use some and they are really great.

We go with Fanuc cause my father have build his first machine with the Serie One PLC. And as we have never been dissapointed with fanuc, why not continue to use their products!

If you plan to stripped the machine, consider to go with 24vdc input and output. They are safe and wire can be smaller.